Do you mean "where over 50% of the adult population could vote"?

Since in most democracies approximately half the adult population are women, your question can be re-phrased as which democracy first had both, broad adult suffrage and women voters? That would be the British colony of New Zealand in 1893, followed by the colony of South Australia in 1894 and then the Commonwealth of Australia (no longer a colony) in 1903.